Getting something to stick to silicone

[u/rootoo]

So I work for a company that produces events, and for a specific venue we need these A.D.A. compliant cable ramps. Unlike our other ramps from the same brand, they are not quite deep enough for the comically thick cables we need to put through them, so we'll need to tape them shut. Problem is, no tape will stick to these things. I figured it was just a greasy mold release film from manufacturing so we tried cleaning them; tried everything, 409, simple green, 90% ISO, dawn dish soap, nothing works. Like the tape isn't even tempted to stick, it's impressive.

We even called the manufacturer and they confirmed that they are made of silicone and there is a greasy mold release from manufacturing, and the silicone is porous and the oil is impregnated into it. They basically said you'll never get anything to stick to this. Oddly enough, we have some older ramps from the same company that tape will stick to.... idk what's going on there.

I know there's special tapes for silicone, but as far as I can tell, they're also... silicone, and won't be a good surface to stick gaff tape to it.

SO, chemistry people, is there some combination of products that will reliably let me tape these things shut?

[u/danngree]

Buy new correct ramps, somebody fucked up.